LOS on FTTP

At about 2255 last night, Nov 6h, I received a LOS indication and my mobile 4G service seemed to be offline from our local antenna. Several other users along the fibre routing reported a LOS as well. This morning the services appear normal. The BT service status page showed everything as normal during all this time. Can anybody offer any insight as to what happened and the likelihood of a repeat event?

Exchange is Crowthorne - THCW

Could be a break in the fibre between you and the Head-End, or an issue at the Head-End itself.

LOS basically means there isn't enough light (or any light) reaching the ONT.

In reply to a post by j0hn83:

LOS basically means there isn't enough light (or any light) reaching the ONT.

Not necessarily. I had the dreaded LOS light appear on my ONT a couple of years ago, and the first thing the investigating Engineer did was measure the light loss at all the various points from the ONT to the terminating exchange. However all the light tests were passed so there was nothing physically wrong with the fibre itself. As a last resort, he reconfigured the line at the exchange and that fixed it. He suspected someone at the exchange had messed up my line unintentionally.

I was thinking along those lines, but the confusing part is the loss of the nearby 4G mast and signal. I can’t understand why that would be affected. Could it be due to OR night time engineering works?

Could be any number of reasons. However if its all ok now, I wouldn't worry too much about it happening again as its quite rare to see the LoS light appear on the ONT.

Edited by deleted (Sat 07-Nov-20 14:10:38)